How to query hash value in Ethereum
Publish: 2021-05-23 13:05:06
1. At the top of Ethereum is DAPP. It exchanges with the smart contract layer through Web3. JS. All smart contracts run on EVM (Ethereum virtual machine) and use RPC calls. Below EVM and RPC are the four core contents of Ethereum, including: blockchain, consensus algorithm, mining and network layer. Except DAPP, all other parts are in the Ethereum client. The most popular Ethereum client is geth (go Ethereum)
2.
transactions.forEach(function(tx){
vartxInfo=web3.eth.getTransaction(tx.transactionHash);
/ / at this time, the transaction information txinfo can be stored in the database
})< br />});
If you want to query the transaction records on the main network, you can use Etherscan. However, if you build your own private chain, how should you query the transaction records
the answer is that you need to listen to the logs on the chain, save them in the database, and then query them in the database. For example:
< pre t = "code" L = "Java" > varaddr = & quot& quot;< br />varfilter=web3.eth.filter({fromB lock:0 ,toBlock:' latest', address:addr });< br />filter.get(function(err,transactions){transactions.forEach(function(tx){
vartxInfo=web3.eth.getTransaction(tx.transactionHash);
/ / at this time, the transaction information txinfo can be stored in the database
})< br />});
Web3. Eth. Filter() is used to monitor the log on the chain, and Web3. Eth. Gettransaction() is used to extract the information of the specified transaction. Once the transaction information is obtained, it can be stored in the database for query
recommend a practical introction, you can see: Ethereum tutorial
3. Just focus:
you can't retrieve your assets through Ethereum block query
think too much
if you want to check the real estate,
you can go to the real estate transaction registration center.
you can't retrieve your assets through Ethereum block query
think too much
if you want to check the real estate,
you can go to the real estate transaction registration center.
4. With the blockchain browser, bitcoin has its own browser. Ethereum and bitcoin are both used. The token based on Ethereum can also be queried on Ethereum's blockchain browser, and usdt can be queried on bitcoin's blockchain browser
5. Many people are optimistic about the decentralized exchange. The private key is in their own hands and they enjoy complete control over the user's assets. However, e to the congestion of Ethereum's public chain, the trading experience of the decentralized exchange on Ethereum is not very good and slow. At present, the most promising is the X protocol, but if the problem of Ethereum is not solved, its application problems can not be started at all
in comparison, the decentralized exchange based on EOS is much better, because its TPS is fast enough to handle the decentralized application at the present stage, and its speed is much better than that on Ethereum. Whaleex, in particular, is very smooth in use, with fast transactions. It is not inferior to those centralized exchanges. Among all decentralized exchanges, whaleex is excellent
therefore, I think the decentralized exchange on EOS may break out faster than that on Ethereum, especially the whale exchange, which will be a dark horse. The smart contract of their home is also the only one that has passed the slow fog security audit. The security is particularly high and the use is assured.
in comparison, the decentralized exchange based on EOS is much better, because its TPS is fast enough to handle the decentralized application at the present stage, and its speed is much better than that on Ethereum. Whaleex, in particular, is very smooth in use, with fast transactions. It is not inferior to those centralized exchanges. Among all decentralized exchanges, whaleex is excellent
therefore, I think the decentralized exchange on EOS may break out faster than that on Ethereum, especially the whale exchange, which will be a dark horse. The smart contract of their home is also the only one that has passed the slow fog security audit. The security is particularly high and the use is assured.
6. Where are you going? Wallet or exchange
transfer eth, as long as there is an address, you can transfer it out
mnemonic words are things that you can help to find when you forget your key, not related to money collection.
transfer eth, as long as there is an address, you can transfer it out
mnemonic words are things that you can help to find when you forget your key, not related to money collection.
7. the stone back. Now the big
8. The withdrawal of digital currency generally only occurs on the digital currency trading platform. Where to withdraw cash? It is suggested to check the account number of the accounting platform carefully. It is generally in the personal center. The specific situation still needs to consult the official personnel, and the answer given by the official shall prevail. However, when choosing a digital currency trading platform, it is better to choose a big platform such as Xigu digital asset trading platform and bitcoin China.
9. A: document - & gt; hash
hash-> Data field of Ethereum transaction
broadcast transaction (chain customer)
at the same time, data storage on the chain can be realized in two ways:
1. After data is organized in a certain form, it is put into the data field of transaction, which is not very flexible, but relatively simple
2. Write the contract and store it in the state variable of the contract.
hash-> Data field of Ethereum transaction
broadcast transaction (chain customer)
at the same time, data storage on the chain can be realized in two ways:
1. After data is organized in a certain form, it is put into the data field of transaction, which is not very flexible, but relatively simple
2. Write the contract and store it in the state variable of the contract.
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